is this a peltzier effect 1? like you can take in ur car or an actual fridge? with the peltzier 1s its hard to get more than a couple of degrees drop unleass its a real small tank like less than 10l. a small fridge pulled to bits with tubing for water wrapped around the evaporator then insulated would do but a lot of work and fridges arent cheaps, could also do this with a dehumidifier there is articles on this if u google them, the water cooler 1s on the net may work if u are using a refridgant powered 1 and u adjust the thermostat on the back, but agin not cheap and the peltzier water coolers wont have enuff power to do it